Heat exchanger

ABSTRACT

A heat exchanger according to the present invention comprises a heat exchange portion in which heating medium flow paths, where a heating medium flows through a space between a plurality of plates, and combustion gas flow paths through which a combustion gas combusted in a burner flows are adjacently and alternatingly formed, wherein the heat exchange portion comprises a sensible heat portion, which surrounds the outside of a combustion chamber and comprises an area on one side of the plates, for heating the heating medium using the sensible heat of the combustion gas generated by combustion of the burner, and a latent heat portion, which comprises an area on the other side of the plates, for heating the heating medium using the latent heat of water vapors in the combustion gas which has completed heat exchanging in the sensible heat portion, wherein a connection passage for the heating medium is formed between the sensible heat portion and the latent heat portion, the latent heat portion comprises a heating medium inlet through which the heating medium is introduced, and a plurality of latent heat portion heating medium flow paths which are formed between the plurality of plates and communicate with the heating medium inlet in parallel, and wherein the sensible heat portion comprises a heating medium outlet through which the heating medium is discharged, and a plurality of sensible heat portion heating medium flow paths which are formed between the plurality of plates and are connected serially between the latent heat portion heating medium flow paths and the heating medium outlet.

TECHNICAL FIELD

The present invention relates to a heat exchanger, and moreparticularly, to a heat exchanger having a simplified assembly structuredue to stacking of a plurality of unit plates to integrally form asensible heat portion and a latent heat portion, and capable of securinga wide heat transfer area between a heating medium and a combustion gasby reducing flow resistance of the heating medium and forming a longflow path for the heating medium in a limited space.

BACKGROUND ART

A boiler used for heating or warm water is a device configured to heat adesired area or supply warm water by heating water or direct water(hereinafter referred to as a “heating medium”) being heated by a heatsource, and the boiler includes a burner configured to combust a mixtureof a gas and air and a heat exchanger configured to transfer combustionheat of a combustion gas to the heating medium.

Boilers produced in an early on used a heat exchanger which heats aheating medium using only sensible heat generated when a burner performsa combustion operation, but a condensing boiler, which has a sensibleheat exchanger configured to absorb sensible heat of a combustion gasgenerated in a combustion chamber, and a latent heat exchangerconfigured to absorb latent heat generated by condensation of watervapor contained in the combustion gas which underwent heat exchange inthe sensible heat exchanger, is recently being used to improve thermalefficiency. Such a condensing boiler is being applied to an oil boileras well as a gas boiler, thereby contributing to an increase in boilerefficiency and a reduction in fuel cost.

As described above, a conventional condensing type heat exchangerincluding a sensible heat exchanger and a latent heat exchanger isconfigured with a structure in which a blower, a fuel supply nozzle, anda burner are installed above a housing, and the sensible heat exchangerand the latent heat exchanger, which each have a heat exchange fincoupled to an outer side of a heat exchange tube, are sequentiallyinstalled inside the housing below the burner.

However, in the conventional condensing type heat exchanger, there is aproblem in that a volume of the heat exchanger is increased due to theblower being disposed above the housing and the structures of thesensible heat exchanger and the latent heat exchanger which areindividually installed inside the housing.

As prior art for improving heat exchange efficiency and minimizing avolume while resolving such a problem, Korean Registered Patent No.10-0813807 discloses a heat exchanger configured with a burner disposedat a central portion of the heat exchanger, and with a heat exchangetube wound around a circumference of the burner in the form of a coil.

The heat exchanger disclosed in the above-described patent has problemsin that the tube is deformed into a rounded shape when the tube isformed into a flat shape and a pressure is applied to a heat transfermedium portion, and a thickness of the tube is to be thick since thetube is manufactured by being rolled up.

Further, the conventional heat exchanger is configured with a structurein which a heat exchange tube is wound around a combustion chamber inthe form of a coil, and a heating medium flows in only one directionalong the heat exchange tube such that there is a disadvantage of beingunable to secure a wide heat transfer area since a heat exchange betweena combustion gas and the heating medium is performed only in a localspace formed around the heat exchanger in the form of a coil.

DISCLOSURE Technical Problem

The present invention has been proposed to resolve the above-describedproblems, and it is an objective of the present invention to provide aheat exchanger having improved heat efficiency by reducing flowresistance of a heating medium and forming a long flow path for theheating medium in a limited space, thereby securing a wide heat transferarea between the heating medium and a combustion gas.

Technical Solution

To achieve the above-described objectives, a heat exchanger of thepresent invention includes a heat exchange portion (200) in whichheating medium flow paths through which a heating medium flows in aspace between a plurality of plates and combustion gas flow pathsthrough which a combustion gas combusted in a burner (100) flows arealternately formed to be adjacent to each other, wherein the heatexchange portion (200) is configured with a sensible heat portion (200A)configured to surround an outer side of a combustion chamber (C),configured with an area at one side of a plate, and configured to heatthe heating medium using sensible heat of the combustion gas generatedby the combustion in the burner (100); and a latent heat portion (200B)configured with an area at the other side of the plate and configured toheat the heating medium using latent heat of water vapor contained inthe combustion gas which underwent heat exchange in the sensible heatportion (200A), and a connection passage for the heating medium isformed between the sensible heat portion (200A) and the latent heatportion (200B), the latent heat portion (200B) is configured with aheating medium inlet (201) into which the heating medium flows, and witha plurality of latent heat portion heating medium flow paths (P1) formedbetween a plurality of plates and configured to communicate with theheating medium inlet (201) in parallel thereto, and the sensible heatportion (200A) is configured with a heating medium outlet (202) throughwhich the heating medium flows and a plurality of sensible heat portionheating medium flow paths (P3) formed between the plurality of platesand connected in series between the plurality of latent heat portionheating medium flow paths (P1) and the heating medium outlet (202).

Advantageous Effects

In accordance with a heat exchanger of the present invention, aplurality of unit plates manufactured in similar patterns are stacked tointegrally form a latent heat portion having multiple parallel heatingpaths and a sensible heat portion having serial heating medium flowpaths, so that flow resistance of a heating medium is reduced and amaximally long flow path for the heating medium is formed in a limitedspace such that heat efficiency between the heating medium and acombustion gas can be maximized.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a heat exchanger according to oneembodiment of the present invention.

FIG. 2 is a right side view of the heat exchanger according to oneembodiment of the present invention.

FIG. 3 is a front view of the heat exchanger according to one embodimentof the present invention.

FIG. 4 is an exploded perspective view of the heat exchanger accordingto one embodiment of the present invention.

FIG. 5 is an enlarged perspective view of a portion of a unit plateshown in FIG. 4.

FIG. 6 is a perspective view illustrating a flow path of a heatingmedium passing through a latent heat portion and a sensible heatportion.

FIG. 7 is a perspective view taken along line A-A of FIG. 3.

FIG. 8 is a perspective view taken along line B-B of FIG. 3.

FIG. 9 is a perspective view taken along line C-C of FIG. 3.

FIG. 10 is a perspective view taken along line D-D of FIG. 3.

FIG. 11 is a perspective view taken along line E-E of FIG. 3.

FIG. 12 is a perspective view taken along line F-F of FIG. 3.

FIG. 13 is a perspective view taken along line G-G of FIG. 3.

FIG. 14 is a perspective view taken along line H-H of FIG. 3.

FIG. 15 is a perspective view taken along line I-I of FIG. 3.

FIG. 16 is a perspective view illustrating a state in which a combustiongas pass-through portion is formed at a lower portion of the latent heatportion.

FIG. 17 is a diagram illustrating a state in which the heating medium isguided in a direction toward an inner side of a combustion chamber by aguide portion.

FIG. 18 is a perspective view of a heat exchanger according to anotherembodiment of the present invention.

FIG. 19 is a front view of FIG. 18.

FIG. 20 is a perspective view taken along line J-J of FIG. 19.

DESCRIPTION OF REFERENCE NUMERALS

1 and 1′: heat exchangers 100: burner 200: heat exchange portion 200A:sensible heat portion 200B: latent heat portion 200B-1: first latentheat portion 200B-2: second latent heat portion 200-1 to 200-12: unitplates 200A-1 to 200a-12: first plates 200b-1 to 200b-12: second plates200-A: first plate group 200-B: second plate group 200-C: third plategroup 201: heating medium inlet 202: heating medium outlet 210: firstplane portion 220: first protrusion 221: first guide portion 222: firstgap maintaining portion 230: second protrusion 240: first flange 241:first incised portion 250: second plane portion 260: first recess 261:second guide portion 262: second gap maintaining portion 270: secondrecess 280: second flange 281: second incised portion 290: heatingmedium blocking portion 300: combustion gas discharge portion 310: lowercover 311: condensation discharge pipe 320: combustion gas dischargepipe A1: first opening A2: second opening B: water housing coolingportion B1: first insulating plate B2: second insulating plate C:combustion chamber D: combustion gas pass-through portion H1 to H8:through-holes H3′ and H7′: first blocked portions H4′ and H8′: secondblocked portions H3-1 and H4-1: first flanges H7-1 and H8-1: secondflanges P1: latent heat portion heating medium flow path P1′: heatingmedium connection passage P2: latent heat portion combustion gas flowpath P3: sensible heat portion heating medium flow path P4: sensibleheat portion combustion gas flow path

MODES OF THE INVENTION

Hereinafter, configurations and operations for preferred embodiments ofthe present disclosure will be described in detail with reference to theaccompanying drawings.

Referring to FIGS. 1 to 6, a heat exchanger 1 according to oneembodiment of the present invention includes a burner 100 configured tocombust a mixture of air and fuel to generate combustion heat and acombustion gas; a heat exchange portion 200 provided at a circumferenceof the burner 100 to perform a heat exchange between a heating mediumand the combustion gas generated by the combustion in the burner 100,and constituted by stacking a plurality of plates; and a combustion gasdischarge portion 300 configured to discharge a combustion gas whichpasses through the heat exchange portion 200.

The burner 100 is a cylindrical burner and is assembled by beinginserted into a space of a combustion chamber C provided at the heatexchange portion 200 in a horizontal direction at a front surface,thereby improving convenience of detaching the burner 100 andmaintenance work of the heat exchanger 1.

The heat exchange portion 200 is configured with a sensible heat portion200A configured to surround an outer side of the combustion chamber Cand configured to form one side area of each of the plurality of platesand heat the heating medium using sensible heat of the combustion gasgenerated by the combustion of the burner 100; and a latent heat portion200B configured to form the other side area of each of the plurality ofplates and heat the heating medium using latent heat generated whenwater vapor contained in the combustion gas which underwent heatexchange in the sensible heat portion 200A is condensed.

The plurality of plates are disposed in an upright structure and stackedin a front-rear direction to allow the sensible heat portion 200A to bedisposed at a top part and the latent heat portion 200B to be disposedat a bottom part.

The combustion gas discharge portion 300 is configured with a lowercover 310 covering a lower portion of the latent heat portion 200B, andwith a combustion gas discharge pipe 320 having a side connected to thelower cover 310 and extending upward. A condensation discharge pipe 311configured to discharge condensation generated at the latent heatportion 200B is connected to a lower portion of the lower cover 310.

Configurations and operations of the plurality of plates, the sensibleheat portion 200A, and the latent heat portion 200B, which constitutethe heat exchange portion 200, will be described below.

The heat exchange portion 200 is configured such that the plurality ofplates are stacked from a front side to a rear side, and the sensibleheat portion 200A disposed at the top part and the latent heat portion200B disposed at the bottom part are integrally formed with theplurality of plates.

As one example, the plurality of plates may be configured with first totwelfth unit plates 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, 200-7,200-8, 200-9, 200-10, 200-11, and 200-12, and the unit plates areconfigured with first plates 200 a-1, 200 a-2, 200 a-3, 200 a-4, 200a-5, 200 a-6, 200 a-7, 200 a-8, 200 a-9, 200 a-10, 200 a-11, and 200a-12, which are disposed at front sides of the unit plates, and withsecond plates 200 b-1, 200 b-2, 200 b-3, 200 b-4, 200 b-5, 200 b-6, 200b-7, 200 b-8, 200 b-9, 200 b-10, 200 b-11, and 200 b-12, which aredisposed at back sides of the unit plates.

Referring to FIGS. 7 to 13, a latent heat portion heating medium flowpath P1 and a sensible heat portion heating medium flow path P3 areformed between the first plate and the second plate constituting each ofthe unit plates, and a latent heat portion combustion gas flow path P2and a sensible heat portion combustion gas flow path P4 are formedbetween a second plate constituting a unit plate disposed at one side ofunit plates stacked adjacent to each other and a first plateconstituting a unit plate disposed at the other side thereof.

Referring to FIGS. 4 and 5, the first plate is configured with a firstplane portion 210; a first protrusion 220 protruding from one side ofthe first plane portion 210 toward the front side, having a centralportion at which a first opening A1 is formed, and configured toconstitute the sensible heat portion 200A; a second protrusion 230protruding from the other side of the first plane portion 210 toward thefront side and configured to form the latent heat portion 200B; and afirst flange 240 bent at an edge of the first plate toward the rearside.

In the first plate 200 a-1 disposed at the foremost position of thefirst plate, a heating medium inlet 201 is formed at one side of thelower portion of the latent heat portion 200B, and a heating mediumoutlet 202 is formed at one side of an upper portion of the sensibleheat portion 200A.

In first plates 200 a-2 to 200 a-12 of the first plate, which aresequentially stacked at the rear side of the first plate 200 a-1disposed at the foremost position, a first through-hole H1 is formed atthe one side of the lower portion of the latent heat portion 200B, asecond through-hole H2 is formed at one side of an upper portion of thelatent heat portion 200B, a third through-hole H 3 is formed at one sideof a lower portion of the sensible heat portion 200A, and a fourththrough-hole H 4 is formed at the other side of the upper portion of thesensible heat portion 200 A.

The second plate is configured with a second plane portion 250; a firstrecess 260 recessed at one side of the second plane portion 250 towardthe rear side, having a central portion at which a second opening A2corresponding to the first opening A1 is formed, and configured to formthe sensible heat portion heating medium flow path P3 between the firstprotrusion 220 and the first recess 260; a second recess 270 recessed atthe other side of the second plane portion 250 toward the rear side andconfigured to form the latent heat portion heating medium flow path P1between the second protrusion 230 and the second recess 270; and asecond flange 280 bent at an edge of the second plate toward the rearside.

In the second plate, a fifth through-hole H5 is formed at the one sideof the lower portion of the latent heat portion 200B, a sixththrough-hole H6 is formed at the one side of the upper portion of thelatent heat portion 200B, a seventh through-hole H7 is formed at the oneside of the lower portion of the sensible heat portion 200A, and aneighth through-hole H8 is formed on the other side of the upper portionof the sensible heat portion 200A.

Further, first blocked portions H3′ and H7′ are respectively formed atthe other side of the lower portion of the sensible heat portion 200A inthe first plate 200 a-9 of the ninth unit plate 200-9 and the secondplate 200 b-8 of the eighth unit plate 200-8, and second blockedportions H4′ and H8′ are respectively formed at the one side of theupper portion of the sensible heat portion 200A in the first plate 200a-5 of the fifth unit plate 200-5 and the second plate 200 b-4 of thefourth unit plate 200-4. The first blocked portions H3′ and H7′ and thesecond blocked portions H4′ and H8′ are configured to change a flow pathof the heating medium passing through the sensible heat portion heatingmedium flow path P3 to form a serial flow path, and operations thereofwill be described below.

Meanwhile, referring to FIGS. 10 and 13, first flanges H3-1 and H4-1 arerespectively formed at the through-holes H3 and H4 to protrude towardthe sensible heat portion combustion gas flow path P4, and secondflanges H7-1 and H8-1 are respectively formed at the through-holes H7and H8 to protrude toward the sensible heat portion combustion gas flowpath P4 and to be in contact with ends of the first flanges H3-1 andH4-1.

According to the configurations of the first flanges H3-1 and H4-1 andthe second flanges H7-1 and H8-1, the sensible heat portion heatingmedium flow path P3 and the sensible heat portion combustion gas flowpath P4 are spatially separated and a gap between the sensible heatportion heating medium flow path P3 and the sensible heat portioncombustion gas flow path P4 may also be constantly maintained.

Further, referring to FIGS. 4 and 15, a water housing cooling portion B,which is configured to provide a heating medium connection passage todirect the heating medium which passes through the heating medium flowpath of the latent heat portion 200B so that the heating medium flowsinto the heating medium flow path of the sensible heat portion 200A andto insulate the combustion chamber C, is formed behind the sensible heatportion 200A.

The water housing cooling portion B is configured such that the heatingmedium is filled in a space between a first insulating plate B1 formedat the first plate 200 a-12 of the unit plate 200-12 disposed at therearmost position, and a second insulating plate B2 formed at the secondplate 200 b-12 of the unit plate 200-12. Protrusions and recesses, whicheach have a comb shape, may be formed to intersect each other on thefirst insulating plate B1 and the second insulating plate B2, and thusturbulence is generated in a flow of the heating medium passing throughthe water housing cooling portion B.

According to the configuration of the water housing cooling portion B,heat insulation of the combustion chamber C is possible without separateinsulation being installed to prevent overheating of the heat exchanger1, and thus a wide heating medium connection passage configured toconnect the latent heat portion heating medium flow path P1 and thesensible heat portion heating medium flow path P3 may be secured in aspace between the first insulating plate B1 and the second insulatingplate B2 such that flow path resistance of the heating medium can bereduced. Further, the sensible heat portion heating medium flow path P3through which the heating medium flows is provided at an outer wallsurrounding the combustion chamber C and thus heat insulation of theouter wall of the combustion chamber C is possible such that the heatinsulation of the combustion chamber C may be achieved over an entirearea thereof by the water housing cooling portion B and the sensibleheat portion heating medium flow path P3.

Meanwhile, the second protrusion 230 and the second recess 270 may beformed in comb shapes bent in opposite directions. In this case, whenthe first plate and the second plate are stacked, the first planeportion 210 and the second plane portion 250 are in contact, the latentheat portion heating medium flow path P1 through which the heatingmedium flows is formed between the second protrusion 230 and the secondrecess 270 which are bent in the opposite directions in a single unitplate, and the latent heat portion combustion gas flow path P2 throughwhich the combustion gas flows is formed between the second recess 270of one of adjacently stacked unit plates and the second protrusion 230of the other adjacently stacked unit plate.

As described above, the second protrusion 230 and the second recess 270are configured to be in comb shapes bent in the opposite directions, andthus turbulence is generated in a flow of the heating medium passingthrough the latent heat portion heating medium flow path P1 and in aflow of the combustion gas passing through the latent heat portioncombustion gas flow path P2 such that heat exchange efficiency can beincreased.

Referring to FIGS. 7 and 16, when the first plate and the second plateare stacked, the first flange 240 and the second flange 280 partiallyoverlap each other, and the overlapping portions are weld-coupled suchthat an outer wall of the heat exchange portion 200 is formed.

Further, in a state in which the first flange 240 and the second flange280 of adjacent plates overlap each other, a combustion gas pass-throughportion D through which the combustion gas flowing in the latent heatportion combustion gas flow path P2 passes toward the combustion gasdischarge portion 300 is formed at some portions of the plurality ofplates.

To this end, a plurality of first incised portions 241 are formed at acombustion gas discharge side of the first flange 240, a plurality ofsecond incised portions 281 are formed at a combustion gas dischargeside of the second flange 280, and the combustion gas pass-throughportion D is formed at some portions of the first incised portion 241and the second incised portion 281 when the first plate and the secondplate are stacked.

The combustion gas pass-through portion D is formed at the lower portionof the latent heat portion 200B to be spaced a predetermined distanceapart from each other in a lateral direction and a longitudinaldirection, and thus the combustion gas which passes through the latentheat portion 200B may be distributed and discharged in a uniform flowrate across the entire lower area of the latent heat portion 200B suchthat the combustion gas pass-through portion D serves to prevent noiseand vibration and reduce flow resistance of the combustion gas passingthrough the latent heat portion 200B and discharged to the combustiongas discharge portion 300.

Meanwhile, guide portions 221 and 261 configured to guide the heatingmedium to flow toward the center of the combustion chamber C are formedat the heating medium flow path P3 of the sensible heat portion 200A. Aplurality of guide portions 221 and a plurality of guide portions 261are formed and spaced apart from each other at an outer side portion ofthe sensible heat portion 200A in a circumferential direction thereof.

Here, the outer side portion of the sensible heat portion 200A is anarea between an intermediate portion and an outer end of the sensibleheat portion 200A in a width direction, and refers to an area adjacentto the outer end thereof.

The guide portions 221 and 261 include the plurality of first guideportions 221 protruding from the first plate toward the sensible heatportion heating medium flow path P3, and include the plurality of secondguide portions 261 protruding from the second plate toward the sensibleheat portion heating medium flow path P3 and formed at positionscorresponding to the plurality of guide portions 221.

Referring to FIGS. 11 and 17, a protruding end of the first guideportion 221 and a protruding end of the second guide portion 261 are incontact with each other to enhance coupling strength between the firstplate and the second plate.

The first guide portion 221 may be configured with a first guide 221 adisposed on a front side on the basis of a flow direction of the heatingmedium, a second guide 221 b disposed to be spaced apart in a diagonaldirection from a rear side of the first guide 221 a toward thecombustion chamber C, and a third guide 221 c disposed to be spacedapart from a rear side of the guide 221 a, and the second guide portion261 may also be configured to correspond to the first guide portion 221.

With such configurations of the guide portions 221 and 261, as indicatedby arrows in FIG. 17, since a flow path of the heating medium flowingalong the sensible heat portion heating medium flow path P3 is guided bythe guide portions 221 and 261 in a direction toward the combustionchamber C, a distance between the burner 100 installed inside thecombustion chamber C and the heating medium is shortened so thatcombustion heat of the burner 100 can be effectively transferred to theheating medium and generation of turbulence is promoted in the flow ofthe heating medium such that heat transfer efficiency can be improved.

Referring to FIG. 12, a plurality of first gap maintaining portions 222protruding toward the sensible heat portion combustion gas flow path P4are formed at the first protrusion 220, and a plurality of second gapmaintaining portions 262 are formed at the first recess 260 at positionscorresponding to the plurality of first gap maintaining portions 222 toprotrude toward the sensible heat portion combustion gas flow path P4. Aprotruding end of the first gap maintaining portion 222 and a protrudingend of the second gap maintaining portion 262 are formed to be incontact with each other.

With such configurations of the first gap maintaining portion 222 andthe second gap maintaining portion 262, a gap of the sensible heatportion combustion gas flow path P4 along with the configurations of thefirst flanges H3-1 and H4-1 and the second flanges H7-1 and H8-1, whichare described below, may be constantly maintained, and the couplingstrength between the first plate and the second plate may be enhanced.

Meanwhile, in order to form a local laminar flow in the combustion gasflowing through the sensible heat portion combustion gas flow path P4 toimprove heat exchange efficiency between the combustion gas and theheating medium, a gap, which is a vertically spaced distance, of thesensible heat portion combustion gas flow path P4 is preferably set tobe in a range of 0.8 to 1.6 mm.

Further, as shown in FIGS. 11, 12, and 15, one of the ends of the firstplate and the second plate, which are disposed at the circumference ofthe combustion chamber C, is bent, seamed, and weld-coupled to be inclose contact with the other end. In this case, a length of a seamed endS of the first plate and the second plate is preferably set to be in arange of 1 to 5 mm to prevent overheating of the seamed end S andmaintain welding quality.

Meanwhile, referring to FIG. 17, a width El of a side area facing thelatent heat portion 200B is preferably formed to be greater than a widthE2 of a side area opposite the latent heat portion 200B among areas ofthe plate constituting the sensible heat portion 200A. This is becausemost of the combustion gas generated in the combustion chamber C flowstoward the latent heat portion 200B, and thus the width El of the sidearea facing the latent heat portion 200B is formed to be greater thanthe width E2 of the side area opposite the latent heat portion 200B tosecure a wider heat transfer area in a region in which a heat exchangeis actively performed.

Flow paths of the combustion gas and the heating medium in the heatexchanger 1 according to the present invention will be described below.

The flow path of the combustion gas will be described first withreference to FIG. 14. In FIG. 14, arrows indicate a flow direction ofthe combustion gas.

The combustion gas generated by the combustion in the burner 100 flowsradially outward inside the combustion chamber C and passes through thesensible heat portion combustion gas flow path P4 formed between theunit plates of the sensible heat portion 200A, and sensible heat of thecombustion gas is transferred to the heating medium passing through thesensible heat portion heating medium flow path P3 while the combustiongas passes through the sensible heat portion combustion gas flow pathP4.

A combustion gas flowing downward via the sensible heat portioncombustion gas flow path P4 flows downward through the latent heatportion combustion gas flow path P2 formed between the unit plates ofthe latent heat portion 200B, and latent heat of condensation containedin water vapor of the combustion gas is transferred to the heatingmedium passing through the latent heat portion heating medium flow pathP1 to preheat the heating medium while the combustion gas flows downwardthrough the latent heat portion combustion gas flow path P2.

A combustion gas reaching a lower portion of the latent heat portioncombustion gas flow path P2 passes through the plurality of combustiongas pass-through portions D which are formed at the lower portion of thelatent heat portion 200B at regular intervals, and is dischargeddownward. At this point, since the combustion gas is distributed anddischarged at a uniform flow rate across the entire lower area of thelatent heat portion 200B due to the plurality of combustion gaspass-through portions D formed at regular intervals, a phenomenon inwhich the combustion gas is biased to one side is prevented such thatthe flow resistance of the combustion gas can be reduced, and generationof noise and vibration can also be minimized.

The combustion gas passing through the plurality of combustion gaspass-through portions D is discharged upward through the lower cover 310and the combustion gas discharge pipe 320, and condensation isdischarged through the condensation discharge pipe 311 connected to thelower portion of the lower cover 310.

The flow path of the heating medium will be described below withreference to FIGS. 4 and 6. In FIGS. 4 and 6, arrows indicate a flowdirection of the heating medium.

The flow path of the heating medium in the latent heat portion 200B willbe described first.

A heating medium flowing into the heating medium inlet 201 formed at thefirst plate 200 a-1, which is disposed at a front surface of theplurality of plates, sequentially passes through the first through-holeH1 and the fifth through-hole H5 respectively formed at the plurality ofplates 200 b-1 to 200 a-12, which are stacked behind the first plate 200a-1, to flow toward the water housing cooling portion B provided betweenthe first plate 200 a-12 and the second plate 200 b-12 of the unit plate200-12 disposed at the rearmost position. Further, some flow amount ofthe heating medium sequentially passing through the first through-holeH1 and the fifth through-hole H5 passes through the latent heat portionheating medium flow path P1 provided inside each of the unit plates200-1 to 200-11 in a parallel structure, sequentially passes through thesecond through-hole H2 and the sixth through-hole H6 which arediagonally disposed with respect to the first through-hole H1 and thefifth through-hole H5, respectively, and flows toward the water housingcooling portion B provided between the first plate 200 a-12 and thesecond plate 200 b-12.

As described above, since the heating medium flow paths of the latentheat portion 200B are provided in a multiple parallel structure, flowresistance of the heating medium passing through the latent heat portionheating medium flow path P1 is reduced, and, since the latent heatportion heating medium flow path P1 and the latent heat portioncombustion gas flow path P2 are alternately disposed to be adjacent toeach other, the heating medium passing through the latent heat portionheating medium flow path P1 may be preheated by effectively absorbingthe latent heat of the water vapor contained in the combustion gas.

Next, the flow path of the heating medium in the sensible heat portion200A will be described.

The heating medium which passes through the water housing coolingportion B absorbs heat transferred to the rear side of the combustionchamber C, and then sequentially passes through a third through-hole H3formed at the first plate 200 a-12 of the twelfth unit plate 200-12 andthird through-holes H3 and seventh through-holes H7 formed at the plates200 b-11 to 200 b-9 stacked in front of the twelfth unit plate 200-12.

Further, since the first blocked portions H3′ and H7′ are formed at theplates 200 a-9 and 200 b-8 stacked at the front side, some of theheating medium sequentially passing through the third through-holes H3and the seventh through-holes H7 and flowing into the sensible heatportion heating medium flow path P3 formed at each of the unit plates200-12 to 200-9 branches off in both directions, flows in the directionstoward the fourth through-hole H4 and the eighth through-hole H8 whichare respectively disposed to be diagonal to the third through-hole H3and the seventh through-hole H7, and then sequentially passes throughthe fourth through-hole H4 and the eighth through-hole H8 to flow to thefront side.

The heating medium which passes through the fourth through-hole H4 andthe eighth through-hole H8 of the plates 200 a-9 and 200 b-8sequentially passes through a fourth through-hole H4 and an eighththrough-hole H8 which are respectively formed at the plates 200 a-8 to200 b-5 sequentially stacked in front of the plates 200 a-9 and 200 b-8.

Further, since the second blocked portions H4′ and H8′ are formed at theplates 200 a-5 and 200 b-4 stacked at the front side, some of theheating medium sequentially passing through the fourth through-holes H4and the eighth through-holes H7 and flowing into the sensible heatportion heating medium flow path P3 formed at each of the unit plates200-8 to 200-5 branches off in both directions, flows in directionstoward the third through-hole H3 and the seventh through-hole H7 whichare respectively disposed to be diagonal to the fourth through-hole H4and the eighth through-hole H8, and then sequentially passes through thethird through-hole H3 and the seventh through-hole H7 to flow to thefront side.

The heating medium which passes through the third through-hole H3 andthe seventh through-hole H7 of the plates 200 a-5 and 200 b-4sequentially passes through the third through-hole H3 and the sevenththrough-hole H7 which are respectively formed at the plates 200 a-4 to200 b-1 sequentially stacked in front of the plates 200 a-5 and 200 b-4.

Further, since portions of the plate 200 a-1 disposed at the foremostposition and corresponding to the third through-hole H3 and the sevenththrough-hole H7 are blocked, some of the heating medium sequentiallypassing through the third through-holes H3 and the seventh through-holesH7 and flowing into the sensible heat portion heating medium flow pathP3 formed at each of the unit plates 200-4 to 200-1 branches off in bothdirections, flows in directions toward the fourth through-hole H4 andthe eighth through-hole H8 which are respectively disposed diagonal tothe third through-hole H3 and the seventh through-hole H7, and thensequentially passes through the fourth through-hole H4 and the eighththrough-hole H8 to be discharged through the heating medium outlet 202formed at the plate 200 a-1 disposed at the foremost position.

FIG. 6 illustrates the above-described flow paths of the heating mediumin the latent heat portion 200B and the sensible heat portion 200A as aunit of a plate group, and in the present embodiment, an example inwhich a first plate group 200-A, a second plate group 200-B, and a thirdplate group 200-C, which are each configured with a set of eight plates,are configured from the front side to the rear side, has been described,but the total number of stacked plates and the number of platesconstituting each of the plate groups in the present invention may bechanged and implemented.

As described above, since the flow paths of the heating medium in thesensible heat portion 200A are configured to be connected in series, theflow path of the heating medium may be formed to be maximally longwithin a limited space of the sensible heat portion 200A such that heatexchange efficiency between the heating medium and the combustion gascan be significantly improved.

A configuration of a heat exchanger 1′ according to another embodimentof the present invention will be described below with reference to FIGS.18 to 20.

The heat exchanger 1′ according to the present embodiment differs fromthe heat exchanger 1 according to the above-described embodiment interms of a heating medium flow path of a latent heat portion 200B, andthe other configurations thereof are the same as those of heat exchanger1. Therefore, the same reference numerals are assigned to members thesame as those of the above-described embodiment, and descriptionsthereof will be omitted.

In the heat exchanger 1′ according to the present embodiment, the latentheat portion 200B is divided into a first latent heat portion 200B-1 anda second latent heat portion 200B-2 on both sides of a heating mediumblocking portion 290, and heating medium flow paths of the first latentheat portion 200B-1 and the second latent heat portion 200B-2 areconfigured in a communicating structure using a heating mediumconnection passage P1′ formed at one side of the heating medium blockingportion 290.

Through-holes H1 and H5 communicating with a heating medium inlet 201and a heating medium flow path of the first latent heat portion 200B-1are formed at one side of a lower portion of the first latent heatportion 200B-1, and through-holes H2 and H6 communicating with a heatingmedium flow path of the second latent heat portion 200B-2 and a sensibleheat portion heating medium flow path P3 are formed at one side of anupper portion of the second latent heat portion 200B-2.

With such a configuration, as indicated by arrows in FIG. 19, a heatingmedium flowing in through the heating medium inlet 201 moves to one sidealong the heating medium flow path of the first latent heat portion200B-1, passes through the heating medium connection passage P1′, isreversed in its flow direction to move to the other side along theheating medium flow path of the second latent heat portion 200B-2, andthen flows along a water housing cooling portion B and the sensible heatportion heating medium flow path P3 as described in the above-describedembodiment.

According to the present embodiment, the heating medium flow path in thelatent heat portion 200B can be formed to be longer than in theabove-described embodiment, and thus absorption efficiency of latentheat can be further improved.

1. A heat exchanger comprising: a heat exchange portion (200) in which aheating medium flow path through which a heating medium flows in a spacebetween a plurality of plates and combustion gas flow paths throughwhich a combustion gas combusted in a burner (100) flows are alternatelyformed to be adjacent to each other, wherein the heat exchange portion(200) is configured with a sensible heat portion (200A) configured tosurround an outer side of a combustion chamber (C), configured with anarea at one side of a plate, and configured to heat the heating mediumusing sensible heat of the combustion gas generated by the combustion inthe burner (100); and a latent heat portion (200B) configured with anarea at the other side of the plate and configured to heat the heatingmedium using latent heat of water vapor contained in the combustion gaswhich underwent heat exchange in the sensible heat portion (200A), aconnection passage for the heating medium is formed between the sensibleheat portion (200A) and the latent heat portion (200B), the latent heatportion (200B) is configured with a heating medium inlet (201) intowhich the heating medium flows, and with a plurality of latent heatportion heating medium flow paths (P1) formed between a plurality ofplates and configured to communicate with the heating medium inlet (201)in parallel thereto, and the sensible heat portion (200A) is configuredwith a heating medium outlet (202) through which the heating mediumflows, and with a plurality of sensible heat portion heating medium flowpaths (P3) formed between the plurality of plates and connected inseries between the plurality of latent heat portion heating medium flowpaths (P1) and the heating medium outlet (202).
 2. The heat exchanger ofclaim 1, wherein: a plurality of plates are formed by stacking aplurality of unit plates in each of which a first plate and a secondplate are stacked, the heating medium flow path is formed between thefirst plate and the second plate of the unit plate, and the combustiongas flow path is formed between a second plate constituting a unit platedisposed at one side of adjacently stacked unit plates and a first plateof a unit plate disposed at the other side thereof.
 3. The heatexchanger of claim 2, wherein: the first plate is configured with afirst plane portion (210); a first protrusion (220) protruding from oneside of the first plane portion (210) to a front side and having a firstopening (A1) formed at a center of the first protrusion (220) toconstitute the sensible heat portion (200A); and a second protrusion(230) protruding from the other side of the first plane portion (210) tothe front side and configured to form the latent heat portion (200B),and the second plate is configured with a second plane portion (250); afirst recess (260) recessed at one side of the second plane portion(250) toward the rear side, configured to form a sensible heat portionheating medium flow path (P3) between the first protrusion (220) and thefirst recess (260), and having a second opening (A2) corresponding tothe first opening (A1); and a second recess (270) recessed at the otherside of the second plane portion (250) toward the rear side andconfigured to form a latent heat portion heating medium flow path (P1)between the second protrusion (230) and the second recess (270).
 4. Theheat exchanger of claim 3, wherein, when the first plate and the secondplate are stacked, the first plane portion (210) and the second planeportion (250) are in contact with each other, and the second protrusion(230) and the second recess (270) are configured to be in comb shapesbent in opposite directions.
 5. The heat exchanger of claim 3, wherein:a plurality of first gap maintaining portions (222) are formed at thefirst protrusion (220) to protrude toward the combustion gas flow path,and a plurality of second gap maintaining portions (262) are formed atthe first recess (260) at positions corresponding to the plurality offirst gap maintaining portions (222) to protrude toward the combustiongas flow path.
 6. The heat exchanger of claim 5, wherein a protrudingend of each of the plurality of first gap maintaining portions (222) anda protruding end of each of the plurality of second gap maintainingportions (262) are formed to be in contact with each other.
 7. The heatexchanger of claim 1, wherein: a sensible heat portion combustion gasflow path (P4) is provided between the sensible heat portion heatingmedium flow paths (P3), and a latent heat portion combustion gas flowpath (P2) communicating with the sensible heat portion combustion gasflow path (P4) is provided between the latent heat portion heatingmedium flow paths (P1).
 8. The heat exchanger of claim 1, wherein:through-holes (H1) and (H5) provided at one side of the latent heatportion (200B) and through-holes (H2) and (H6) provided at the otherside, which communicate with the latent heat portion heating medium flowpaths (P1), are diagonally formed at the latent heat portion (200B) toconnect the latent heat portion heating medium flow paths (P1) inparallel, and through-holes (H3) and (H7) provided at one side of thesensible heat portion (200A) and through-holes (H4) and (H8) provided atthe other side, which communicate with the sensible heat portion heatingmedium flow paths (P3), are diagonally formed at the sensible heatportion (200A) to connect the sensible heat portion heating medium flowpaths (P3) in series.
 9. The heat exchanger of claim 1, wherein: thelatent heat portion (200B) is divided into a first latent heat portion(200B-1) and a second latent heat portion (200B-2) on both sides of aheating medium blocking portion (290), the heating medium flow paths ofthe first latent heat portion (200B-1) and the second latent heatportion (200B-2) communicate through a heating medium connection passage(P1′) formed at one side of the heating medium blocking portion (290),through-holes (H1) and (H5) communicating with the heating medium inlet(201) and the heating medium flow path of the first latent heat portion(200B-1) are formed at one side of the first latent heat portion(200B-1), and through-holes (H2) and (H6) communicating with the heatingmedium flow path of the second latent heat portion (200B-2) and thesensible heat portion heating medium flow path (P3) are formed at oneside of the second latent heat portion (200B-2).
 10. The heat exchangerof claim 8, wherein: a heating medium flowing into the sensible heatportion heating medium flow path (P3) through the through-holes (H3) and(H7) provided at the one side branches off in both directions and flowstoward the through-holes (H4) and (H8) formed at the other side in adiagonal direction, and the heating medium flowing into the sensibleheat portion heating medium flow path (P3) through the through-holes(H4) and (H8) branches off in both directions and flows toward thethrough-holes (H3) and (H7) formed at the one side in the diagonaldirection.
 11. The heat exchanger of claim 10, wherein: first blockedportions (H3′) and (H7′) configured to guide the heating medium, whichflows into the sensible heat portion heating medium flow path (P3)through the through-holes (H3) and (H7) provided at the one side, toflow toward the through-holes (H4) and (H8) formed at the other side inthe diagonal direction, and second blocked portions (H4′) and (H8′)configured to guide the heating medium, which flows into the sensibleheat portion heating medium flow path (P3) through the through-holes(H4) and (H8) provided at the other side, to flow toward thethrough-holes (H3) and (H7) formed at the one side in the diagonaldirection are formed at the sensible heat portion (200A).
 12. The heatexchanger of claim 8, wherein: first flanges (H3-1) and (H4-2) arerespectively formed at the through-holes (H3) and (H4) to protrudetoward the combustion gas flow path, and second flanges (H7-1) and(H8-1) are respectively formed at the through-holes (H7) and (H8) toprotrude toward the combustion gas flow path and are in contact withends of the first flanges (H3-1) and (H4-2).
 13. The heat exchanger ofclaim 9, wherein: a heating medium flowing into the sensible heatportion heating medium flow path (P3) through the through-holes (H3) and(H7) provided at the one side branches off in both directions and flowstoward the through-holes (H4) and (H8) formed at the other side in adiagonal direction, and the heating medium flowing into the sensibleheat portion heating medium flow path (P3) through the through-holes(H4) and (H8) branches off in both directions and flows toward thethrough-holes (H3) and (H7) formed at the one side in the diagonaldirection.